Anti-leucine-rich glioma-inactivated 1 limbic encephalitis: A case report and literature review

Abstract

Abstract. This study describes the case of a 41-year-old woman admitted for anterograde memory loss, right facial grimacing and right arm posturing that had begun 1 month previously. Cranial magnetic resonance-diffusion weighted imaging and -fluid-attenuated inversion recovery imaging revealed a hyperintense signal in the left hippocampus and right basal ganglia, but no contrast enhancement. An electroencephalogram revealed rhythmic sharp and slow waves and rhythmic θ build-ups in the left temporal area. Single-photon emission computed tomography showed increased regional blood flow perfusion in the left cerebral frontal lobe and the right basal ganglia. The cerebrospinal fluid was normal, with the exception of the presence of leucine-rich glioma-inactivated 1 (LGI1) antibodies, and LGI1 antibodies were also found in the blood serum. The presence of the antibodies, the faciobrachial dystonic seizures (FBDSs) and the memory loss indicated limbic encephalitis. After 3 months of immunotherapy, the patient was free from epileptic seizures and had undergone a partial memory restoration. FBDSs alone justify the immediate initiation of immunotherapy, even prior to laboratory confirmation of the disease, as early treatment limits the duration of the illness.

Paraneoplastic Neurologic Syndromes: Rare But More Common Than Expected Nine Cases with a Literature Review

“…Anti-LGI1 antibodies are against the VGKC complex and are mostly expressed in the hippocampus (7). Hippocampal involvement was also observed in our patient's MRI.…”

LGI1 antibody‐associated limbic encephalitis started from unilateral basal ganglia to medial temporal lobe and insula

“…Abnormal hyperintensities on her brain MRI first appeared in the unilateral right caudate nucleus and putamen (Figure 1A-B), which is a rare feature in this disease as previous reports have shown that abnormalities mainly involved the bilateral limbic system. 6,7 Some previous papers also reported the involvement of basal ganglia in patients with LGI1 antibody-associated limbic encephalitis, 8,9 but in their cases, the patients responded well to the initial methylprednisolone or intravenous immunoglobulin therapy. In our case, the patient was refractory to the initial methylprednisolone pulse therapy and improved after the additional treatments of plasma exchange and intravenous immunoglobulin.…”

Anti-leucine-rich-glioma-inactivated 1 Limbic Encephalitis: An Underrecognised Disease

“…The autoimmune inflammation can be further categorised on the basis of antibodies against the nuclear antigens (paraneoplastic antibodies), antibodies against the target cell surface antigens (VGKC, NMDA) and those associated with unknown antibody (seronegative limbic encephalitis). 1,6 The VGKCs are situated both in the central nervous system and the peripheral nervous system; and are important regulators of cell action potential. LGI1 and CASPR2 are two of its associated components.…”

“…German researchers were the first to report the neuropathological characteristics of anti-LGI1 limbic encephalitis and suggested a CD8+ T-cell-mediated immune process directed against hippocampal neurons. 6 Others state that LGI1 antibodies belong to IgG 4 subclass; and postulated mode of action is through direct functional interference. 4 The disease has the characteristics of sub-acute memory and cognitive disturbance, behavioural changes, usually accompanied by seizures.…”

“…4 Few reports have mentioned the presence of reversible insomnia, associated with limbic encephalitis. 4,6 Autoimmune encephalitis should be considered in patients presenting with sub-acute encephalopathy.…”